let shopArray = [
    {pcode: 1, pname: "面包", price: 4, num: 3},
    {pcode: 2, pname: "寿司", price: 15, num: 2},
    {pcode: 3, pname: "薯片", price: 5, num: 4},
    {pcode: 4, pname: "火腿肠", price: 6, num: 5},
    {pcode: 5, pname: "方便面", price: 3, num: 10},
    {pcode: 6, pname: "三明治", price: 7, num: 6},
    {pcode: 7, pname: "牛排", price: 20, num: 1},
    {pcode: 8, pname: "关东煮", price: 10, num: 2}
];